Even when we can reasonably understand it it's still a tragedy that we can't provide a better alternative. Wether that is working therapy, cures for other illnesses, medication that make life enjoyable or any other change to society.
Viewing it as a tragedy isn't in itself invalidating, it can be a way of viewing the issue as a means to progress.
But I do agree that just blurting it out and pasting it places is inconsiderate, and not acknowledging the current reality of people's situations don't make them better.
People often have very reasonable reasons they want to kill themselves. Doesn't mean they should necessarily do it, but such statements are invalidating or unhelpful to the suicidal.
I think ultimately people just want to be understood.
It's also a little bit cultural isn't it. For instance Euthanasia is a form of suicide that can be entirely reasonable and made in the absence of mental illness.